Time has a way of messing with one's persepctive - We tend to think of the "wild west" as being ages ago, but for a kid like Marty growing up in Arizona in the late 1920's, the OK Corral, Billy the Kid, Geronimo and other similar events in Arizona and New Mexico during the 1880s were not too ancient history. Any one over 50 probably remembered living through the events personally - kind of like I remember Elvis, Sputnik and JFK (at least I think I do).